Methods for depositing material onto microfeature workpieces in reaction chambers and systems for depositing materials onto microfeature workpieces

ABSTRACT

Methods for depositing material onto microfeature workpieces in reaction chambers and systems for depositing materials onto microfeature workpieces are disclosed herein. In one embodiment, a method includes depositing molecules of a gas onto a microfeature workpiece in the reaction chamber and selectively irradiating a first portion of the molecules on the microfeature workpiece in the reaction chamber with a selected radiation without irradiating a second portion of the molecules on the workpiece with the selected radiation. The first portion of the molecules can be irradiated to activate the portion of the molecules or desorb the portion of the molecules from the workpiece. The first portion of the molecules can be selectively irradiated by impinging the first portion of the molecules with a laser beam or other energy source.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. application Ser. No. 10/840,571filed May 6, 2004, now U.S. Pat. No. 8,133,554, which is incorporatedherein by reference in its entirety.

TECHNICAL FIELD

The present invention is related to methods for depositing material ontomicrofeature workpieces in reaction chambers and systems for depositingmaterials onto microfeature workpieces. More particularly, the presentinvention is related to methods for irradiating a portion of amicrofeature workpiece to desorb or activate molecules in that portionof the workpiece.

BACKGROUND

Thin film deposition techniques are widely used in the manufacturing ofmicrofeatures to form a coating on a workpiece that closely conforms tothe surface topography. The size of the individual components in theworkpiece is constantly decreasing, and the number of layers in theworkpiece is increasing. As a result, both the density of components andthe aspect ratios of depressions (i.e., the ratio of the depth to thesize of the opening) are increasing. Thin film deposition techniquesaccordingly strive to produce highly uniform conformal layers that coverthe sidewalls, bottoms, and corners in deep depressions that have verysmall openings.

One widely used thin film deposition technique is Chemical VaporDeposition (CVD). In a CVD system, one or more precursors capable ofreacting to form a solid thin film are mixed while in a gaseous orvaporous state, and then the precursor mixture is presented to thesurface of the workpiece. The surface of the workpiece catalyzes thereaction between the precursors to form a solid thin film at theworkpiece surface. A common way to catalyze the reaction at the surfaceof the workpiece is to heat the workpiece to a temperature that causesthe reaction.

Although CVD techniques are useful in many applications, they also haveseveral drawbacks. For example, if the precursors are not highlyreactive, then a high workpiece temperature is needed to achieve areasonable deposition rate. Such high temperatures are not typicallydesirable because heating the workpiece can be detrimental to thestructures and other materials already formed on the workpiece.Implanted or doped materials, for example, can migrate within thesilicon substrate at higher temperatures. On the other hand, if morereactive precursors are used so that the workpiece temperature can belower, then reactions may occur prematurely in the gas phase beforereaching the substrate. This is undesirable because the film quality anduniformity may suffer, and also because it limits the types ofprecursors that can be used.

Atomic Layer Deposition (ALD) is another thin film deposition technique.FIGS. 1A and 1B schematically illustrate the basic operation of ALDprocesses. Referring to FIG. 1A, a layer of gas molecules A coats thesurface of a workpiece W. The layer of A molecules is formed by exposingthe workpiece W to a precursor gas containing A molecules and thenpurging the chamber with a purge gas to remove excess A molecules. Thisprocess can form a monolayer of A molecules on the surface of theworkpiece W because the A molecules at the surface are held in placeduring the purge cycle by physical adsorption forces at moderatetemperatures or chemisorption forces at higher temperatures. Referringto FIG. 1B, the layer of A molecules is then exposed to anotherprecursor gas containing B molecules. The A molecules react with the Bmolecules to form an extremely thin layer of solid material on theworkpiece W. The chamber is then purged again with a purge gas to removeexcess B molecules.

FIG. 2 illustrates the stages of one cycle for forming a thin solidlayer using ALD techniques. A typical cycle includes (a) exposing theworkpiece to the first precursor A, (b) purging excess A molecules, (c)exposing the workpiece to the second precursor B, and then (d) purgingexcess B molecules. In actual processing, several cycles are repeated tobuild a thin film on a workpiece having the desired thickness. Forexample, each cycle may form a layer having a thickness of approximately0.5-1.0 Å, and thus several cycles are required to form a solid layerhaving a thickness of approximately 60 Å.

One drawback of ALD processing is that it has a relatively lowthroughput compared to CVD techniques. For example, each A-purge-B-purgecycle can take several seconds. This results in a total process time ofseveral minutes to form a single thin layer of only 60 Å. In contrast toALD processing, CVD techniques require only about one minute to form a60 Å thick layer. The low throughput limits the utility of the ALDtechnology in its current state because ALD may create a bottleneck inthe overall manufacturing process.

FIG. 3 schematically illustrates a single-wafer CVD/ALD reactor 10having a reaction chamber 20 coupled to a gas supply 30 and a vacuumpump 40. The reactor 10 also includes a gas dispenser 60 and a heater 50for supporting the workpiece W in the reaction chamber 20. The gasdispenser 60 includes a plenum 62 operably coupled to the gas supply 30and a distributor plate 64 having a plurality of holes 66. In operation,the heater 50 heats the workpiece W to a desired temperature, and thegas supply 30 selectively injects the precursors as described above. Thevacuum pump 40 maintains a negative pressure in the reaction chamber 20to draw the gases from the gas dispenser 60 across the workpiece W andthen through an outlet of the chamber 20.

In photoselective CVD processing, the reaction chamber 20 may furtherinclude a laser 70 configured to generate a laser beam 72 for activatingat least one of the precursors. The laser 70 produces the laser beam 72along a beam path generally parallel to the workpiece W, with the laserbeam 72 positioned between the gas dispenser 60 and the workpiece W toselectively activate a precursor(s) before the precursor(s) is depositedonto the workpiece W. The activated precursor(s) subsequently reactswith other precursors on the surface of the workpiece W to form a solidthin film.

In addition to CVD and ALD processing, other processing steps arenecessary to form features and devices on workpieces. For example,conventional processing includes patterning a design onto a workpiece,etching unnecessary material from the workpiece, depositing selectedmaterial onto the workpiece, and planarizing the surface of theworkpiece. These additional processing steps are expensive andtime-consuming. Accordingly, a need exists to improve the efficiencywith which features are formed on workpieces.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are schematic cross-sectional views of stages in ALDprocessing in accordance with the prior art.

FIG. 2 is a graph illustrating a cycle for forming a layer using ALDtechniques in accordance with the prior art.

FIG. 3 is a schematic representation of a system including a reactionchamber for depositing materials onto a microfeature workpiece inaccordance with the prior art.

FIG. 4 is a schematic representation of a system for depositingmaterials onto a microfeature workpiece in accordance with oneembodiment of the invention.

FIGS. 5A-5C illustrate stages in an ALD process in which a laser desorbsmaterial from a workpiece in accordance with another embodiment of theinvention.

FIG. 5A is a schematic side cross-sectional view of a portion of theworkpiece after depositing a layer of first molecules onto a surface ofthe workpiece.

FIG. 5B is a schematic side cross-sectional view of the workpiece afterdesorbing a selected portion of the first molecules.

FIG. 5C is a schematic side cross-sectional view of the workpiece afterdepositing a layer of second molecules onto the workpiece.

FIGS. 6A-6D illustrate stages in a CVD process in which the laserdesorbs material from a workpiece in accordance with another embodimentof the invention.

FIG. 6A is a schematic side cross-sectional view of a portion of theworkpiece after depositing a layer of first molecules onto a surface ofthe workpiece.

FIG. 6B is a schematic side cross-sectional view of the workpiece afterwith the laser desorbing selected first molecules from a portion of theworkpiece.

FIG. 6C is a schematic side cross-sectional view of the workpiece afterdepositing second molecules onto the workpiece.

FIG. 6D is a schematic side cross-sectional view of the workpiece afterdesorbing a selected portion of the second molecules.

FIGS. 7A-7C illustrate stages in an ALD process in which the laseractivates molecules on a workpiece in accordance with another embodimentof the invention.

FIG. 7A is a schematic side cross-sectional view of a portion of theworkpiece after depositing a layer of first molecules onto theworkpiece.

FIG. 7B is a schematic side cross-sectional view of the workpiece afterdepositing a plurality of second molecules onto the workpiece.

FIG. 7C a schematic side cross-sectional view of the workpiece afterremoving the nonreacted second molecules from the workpiece.

FIG. 8 is a schematic representation of a system for depositingmaterials onto a microfeature workpiece in accordance with anotherembodiment of the invention.

FIG. 9 is a schematic representation of a system for depositingmaterials onto a microfeature workpiece in accordance with anotherembodiment of the invention.

DETAILED DESCRIPTION A. Overview

The following disclosure describes several embodiments of systems fordepositing materials onto microfeature workpieces, and methods fordepositing materials onto workpieces in reaction chambers. Many specificdetails of the invention are described below with reference tosingle-wafer reaction chambers for depositing materials ontomicrofeature workpieces, but several embodiments can be used in batchsystems for processing a plurality of workpieces simultaneously. Theterm “microfeature workpiece” is used throughout to include substratesupon which and/or in which microelectronic devices, micromechanicaldevices, data storage elements, read/write components, and otherfeatures are fabricated. For example, microfeature workpieces can besemiconductor wafers such as silicon or gallium arsenide wafers, glasssubstrates, insulative substrates, and many other types of materials.Furthermore, the term “gas” is used throughout to include any form ofmatter that has no fixed shape and will conform in volume to the spaceavailable, which specifically includes vapors (i.e., a gas having atemperature less than the critical temperature so that it may beliquefied or solidified by compression at a constant temperature).Several embodiments in accordance with the invention are set forth inFIGS. 4-9 and the following text to provide a thorough understanding ofparticular embodiments of the invention. A person skilled in the artwill understand, however, that the invention may have additionalembodiments, or that the invention may be practiced without several ofthe details of the embodiments shown in FIGS. 4-9.

Several aspects of the invention are directed to methods for depositingmaterials onto microfeature workpieces in a reaction chamber. In oneembodiment, a method includes depositing molecules of a gas onto amicrofeature workpiece in the reaction chamber and selectivelyirradiating a first portion of the molecules on the microfeatureworkpiece in the reaction chamber with a selected radiation withoutirradiating a second portion of the molecules on the workpiece with theselected radiation. The first portion of the molecules can be irradiatedto activate the molecules or desorb the molecules from the workpiece.The first portion of the molecules can be selectively irradiated byimpinging the molecules with a laser beam or another energy source.

In another embodiment, a method includes depositing first molecules of afirst gas onto the microfeature workpiece in the reaction chamber,directing a laser beam toward a first portion of the first molecules todesorb the first portion of the first molecules without desorbing asecond portion of the first molecules, and depositing second moleculesof a second gas onto the second portion of the first molecules. Thefirst and second gases can have generally the same or differentcompositions. The method can further include directing the laser beamtoward a first portion of the second molecules to desorb the firstportion of the second molecules without directing the laser beam towarda second portion of the second molecules.

In another embodiment, a method includes depositing first molecules of afirst gas onto the microfeature workpiece in the reaction chamber,directing a laser beam toward a selected portion of the first moleculesto activate the selected portion of the first molecules to react withsecond molecules of a second gas, and depositing the second molecules ofthe second gas onto the selected portion of the first molecules. Thefirst and second gases can have the same or different compositions. Themethod can further include purging excess first gas from the reactionchamber before depositing molecules of the second gas.

Other aspects of the invention are directed to systems for depositingmaterials onto a surface of a microfeature workpiece. In one embodiment,a system includes a gas supply assembly having a gas source, a gas phasereaction chamber for carrying the microfeature workpiece, a gasdistributor carried by the reaction chamber and coupled to the gassupply assembly, an energy source positioned to selectively irradiateportions of the microfeature workpiece, and a controller operablycoupled to the energy source and the gas supply assembly. The controllerhas a computer-readable medium containing instructions to perform one ofthe above-mentioned methods.

B. Embodiments of Deposition Systems

FIG. 4 is a schematic representation of a system 100 for depositingmaterials onto a microfeature workpiece W in accordance with oneembodiment of the invention. In this embodiment, the system 100 includesa reactor 110 having a reaction chamber 120 coupled to a gas supply 130and a vacuum pump 140. The reactor 110 also includes a gas distributor160 coupled to the gas supply 130 to dispense gas(es) into the reactionchamber 120 and onto the workpiece W. Byproducts including excess and/orunreacted gas molecules are removed from the reaction chamber 120 by thevacuum pump 140 and/or by injecting a purge gas into the chamber 120.

The gas supply 130 includes a plurality of gas sources 132 (shownschematically and identified individually as 132 a-c) and a plurality ofgas lines 136 coupled to corresponding gas sources 132. The gas sources132 can include a first gas source 132 a for providing a first gas, asecond gas source 132 b for providing a second gas, and a third gassource 132 c for providing a third gas. The first and second gases canbe first and second precursors, respectively. The third gas can be apurge gas. The first and second precursors are the gas and/or vaporphase constituents that react to form the thin, solid layer on theworkpiece W. The purge gas can be a suitable type of gas that iscompatible with the reaction chamber 120 and the workpiece W. In otherembodiments, the gas supply 130 can include a different number of gassources 132 for applications that require additional precursors or purgegases.

The system 100 of the illustrated embodiment further includes a valveassembly 133 (shown schematically) coupled to the gas lines 136 and acontroller 134 (shown schematically) operably coupled to the valveassembly 133. The controller 134 generates signals to operate the valveassembly 133 to control the flow of gases into the reaction chamber 120for ALD and CVD applications. For example, the controller 134 can beprogrammed to operate the valve assembly 133 to pulse the gasesindividually through the gas distributor 160 in ALD applications or tomix selected precursors in the gas distributor 160 in CVD applications.More specifically, in one embodiment of an ALD process, the controller134 directs the valve assembly 133 to dispense a pulse of the first gas(e.g., the first precursor) into the reaction chamber 120. Next, thecontroller 134 directs the valve assembly 133 to dispense a pulse of thethird gas (e.g., the purge gas) to purge excess molecules of the firstgas from the reaction chamber 120. The controller 134 then directs thevalve assembly 133 to dispense a pulse of the second gas (e.g., thesecond precursor), followed by a pulse of the third gas. In oneembodiment of a pulsed CVD process, the controller 134 directs the valveassembly 133 to dispense a pulse of the first and second gases (e.g.,the first and second precursors) into the reaction chamber 120. Next,the controller 134 directs the valve assembly 133 to dispense a pulse ofthe third gas (e.g., the purge gas) into the reaction chamber 120. Inother embodiments, the controller 134 can dispense the gases in othersequences.

In the illustrated embodiment, the reactor 110 also includes a workpiecesupport 150 to hold the workpiece W in the reaction chamber 120. Theworkpiece support 150 can be heated to bring the workpiece W to adesired temperature for catalyzing the reaction between the first gasand the second gas at the surface of the workpiece W. For example, theworkpiece support 150 can be a plate with a heating element. Theworkpiece support 150, however, may not be heated in other applications.

The illustrated reaction chamber 120 further includes a laser 170 (shownschematically) operably coupled to the controller 134 for producing alaser beam 172 to irradiate selected portions of the workpiece W. Thelaser beam 172 provides sufficient localized energy to desorb oractivate the irradiated molecules on the workpiece W. For example, aftera layer of material has been deposited onto the workpiece W, the laser170 can direct the laser beam 172 toward a selected portion of thematerial to desorb or activate the material, as described in greaterdetail below. Depending on the material, the power required fordesorption can be on the order of 1e6 W/cm². Accordingly, in severalembodiments, the laser 170 can be a stand-alone laser system; and inother embodiments, the laser 170 can include one or more laser diodes.For example, suitable laser diodes include a 600 W QCW Laser DiodeArray, part number ARR48P600, manufactured by Cutting Edge Optronics inSt. Charles, Mo. In additional embodiments, the reaction chamber 120 mayinclude an energy source in lieu of a laser to heat a localized portionof the workpiece W for desorbing or activating selected molecules.

The reactor 110 may further include a positioning device 180 (shownschematically) coupled to the laser 170 and operably coupled to thecontroller 134 for moving the laser 170 and aligning the laser beam 172with the selected portion of the workpiece W. For example, thepositioning device 180 can move the laser 170 from a stowed position(shown in hidden lines) to a deployed position (shown in solid lines)for irradiating the selected portion of the workpiece W. In the stowedposition, the laser 170 and the positioning device 180 are arranged soas not to interfere with the flow of gases from the gas distributor 160to the workpiece W. The positioning device 180 can be configured to movethe laser 170 side to side (e.g., X direction) and forward and backward(e.g., Y direction) to align the laser beam 170 with the selectedportion of the workpiece W. Alternatively, the positioning device 180may also be able to move the laser 170 upward and downward (e.g., Zdirection). The positioning device 180 can accordingly have anarticulating arm, a telescoping arm, or other type of structure tosupport the laser 170 over the workpiece W. The positioning device 180can further include an actuator to move the arm. In other embodiments,such as those described below with reference to FIGS. 8 and 9, thereactor may not include a positioning device coupled to the laser.

C. Embodiments of Methods for Depositing Materials Onto Workpieces

FIGS. 5A-5C illustrate stages in an ALD process in which the laser 170desorbs material from the workpiece W in accordance with one embodimentof the invention. FIG. 5A, more specifically, is a schematic sidecross-sectional view of a portion of the workpiece W after dispensing apulse of a first gas into the reaction chamber 120 (FIG. 4) anddepositing a layer of first molecules 192 from the first gas onto asurface 190 of the workpiece W. FIG. 5B is a schematic sidecross-sectional view of the workpiece W with the laser beam 172impinging a selected portion P₁ of the workpiece W. After depositing thefirst molecules 192 onto the workpiece W, the positioning device 180aligns the laser 170 with the selected portion P₁ of the workpiece W andthe laser 170 directs the laser beam 172 toward selected first molecules192 a. The power, wavelength, and other laser beam parameters areselected based on the chemistry of the first molecules 192 so that theenergy from the laser beam 172 breaks the bonds securing the selectedfirst molecules 192 a to the surface 190 and, consequently, desorbs theselected first molecules 192 a from the workpiece W. As the laser 170moves across the workpiece W, the laser beam 172 impinges the selectedfirst molecules 192 a without impinging a plurality of nonselected firstmolecules 192 b. Consequently, the nonselected first molecules 192 bremain physisorbed and/or chemisorbed to the surface 190 of theworkpiece W.

After irradiating the portion P₁ of the workpiece W, a purge gas can bedispensed into the reaction chamber 120 (FIG. 4) to remove the desorbedfirst molecules 192 a and the excess first gas molecules from thechamber 120. Alternatively, the purge gas can be dispensed into thereaction chamber 120 while the portion P₁ of the workpiece W isirradiated. In other embodiments, the desorbed first molecules 192 a canbe removed from the reaction chamber 120 without injecting a purge gasby drawing the molecules 192 a from the chamber 120 with the vacuum pump140 (FIG. 4). In additional embodiments, the desorbed first molecules192 a can be removed from the reaction chamber 120 as a second gas issubsequently injected into the chamber 120 and deposited onto theworkpiece W.

FIG. 5C is a schematic side cross-sectional view of the workpiece Wafter dispensing a pulse of a second gas into the reaction chamber 120(FIG. 4) and depositing a layer of second molecules 194 from the secondgas onto the workpiece W. The second molecules 194 react with the firstmolecules 192 b to form a discrete film 195 a on the workpiece W.

The first and second gases can have the same or different compositions.For example, in one embodiment, the composition of the second molecules194 can be chosen such that the second molecules 194 adhere to thenonirradiated first molecules 192 b but do not adhere to the exposedportion P₁ of the surface 190. Suitable gases for such an embodimentinclude TMA for the first gas and O₃ for the second gas, although othergases can be used. In other embodiments, the second molecules 194 canadhere to the exposed portion P₁ of the surface 190 in addition to thenonirradiated first molecules 192 b. If some of the second molecules 194adhere to the exposed portion P₁ of the surface 190, the laser 170 (FIG.4) can optionally irradiate and desorb these molecules. In either case,after depositing the second molecules 194 onto the workpiece W, thereaction chamber 120 can be purged and the process can be repeated tobuild additional layers (shown in hidden lines as 195 b and 195 c) onthe workpiece W.

In additional embodiments, the laser 170 can irradiate the selectedportion P₁ of the workpiece W only after the second molecules 194 havebeen deposited onto the workpiece W. For example, in one method, thefirst molecules 192 are deposited across the workpiece W, and then thereaction chamber 120 can be optionally purged. Next, the secondmolecules 194 are deposited across the workpiece W, and then the laser170 irradiates the selected portion P₁ of the workpiece W to desorb theselected first and second molecules.

One advantage of the method illustrated in FIGS. 5A-5C is the ability toform features 199, such as conductive lines, on the workpiece W duringan ALD process. Forming features 199 on the workpiece W during thedeposition process simplifies and reduces the number of subsequentproduction steps required to construct devices on the workpiece W. Forexample, by forming the features 199 on the illustrated workpiece Wduring an ALD process, post-deposition processing, including masking,etching, depositing material, and planarizing, may be reduced and/oreliminated.

FIGS. 6A-6D illustrate stages in a CVD process in which the laser 170desorbs material from the workpiece W in accordance with anotherembodiment of the invention. FIG. 6A, more specifically, is a schematicside cross-sectional view of a portion of the workpiece W afterdispensing a pulse of one or more precursors into the reaction chamber120 (FIG. 4), mixing the precursors to form a gas, and depositing alayer of first molecules 292 from the gas onto the surface 190 of theworkpiece W. FIG. 6B is a schematic side cross-sectional view of theworkpiece W with the laser 170 directing the laser beam 172 towardselected first molecules 292 a to desorb the molecules 292 a from aportion P₂ of the workpiece W. As the laser 170 moves across theworkpiece W, the laser beam 172 does not impinge and desorb a pluralityof nonselected molecules 292 b. After desorption, the selected firstmolecules 292 a can be removed from the reaction chamber 120 bydispensing a purge gas into the chamber 120 and/or drawing the desorbedmolecules 292 a from the chamber 120 with the vacuum pump 140 (FIG. 4).Alternatively, the purge gas can be dispensed into the reaction chamber120 while the portion P₂ of the workpiece W is irradiated.

FIG. 6C is a schematic side cross-sectional view of the workpiece Wafter dispensing another pulse of the precursors into the reactionchamber 120 (FIG. 4), mixing the precursors to form the gas, anddepositing a plurality of second molecules 294 of the gas onto theworkpiece W. The second molecules 294 are deposited onto thenonirradiated molecules 292 b and the exposed portion P₂ of theworkpiece W. The second molecules 294 proximate to the first molecules292 b react with the first molecules 292 b to form a discrete film 295 aon the workpiece W.

FIG. 6D is a schematic side cross-sectional view of the workpiece W withthe laser 170 directing the laser beam 172 toward selected secondmolecules 294 a to desorb the selected molecules 294 a from the portionP₂ of the workpiece W. After desorbing the selected second molecules 294a, the process can be repeated to build additional layers (shown inhidden lines as 295 b and 295 c) on the workpiece W. In otherembodiments, the selected second molecules 294 a may not be desorbedfrom the workpiece W or may be desorbed during subsequent process steps.

In additional embodiments, more than one layer of molecules can bedesorbed during a single irradiation cycle. For example, in one method,a layer of first molecules 292 can be deposited onto the workpiece W, alayer of second molecules 294 can be deposited onto the workpiece W, andthen the laser beam 172 can desorb the selected first and secondmolecules 292 a and 294 a from the workpiece W.

FIGS. 7A-7C illustrate stages in an ALD process in which the laser 170activates molecules on the workpiece W in accordance with anotherembodiment of the invention. More specifically, FIG. 7A is a schematicside cross-sectional view of a portion of the workpiece W afterdispensing a pulse of a first gas into the reaction chamber 120 (FIG. 4)and depositing a layer of first molecules 392 (shown as 392 a and 392 b)from the first gas onto the surface 190 of the workpiece W. Afterdepositing the first molecules 392, the reaction chamber 120 canoptionally be purged to remove excess molecules of the first gas. Next,the laser 170 moves across the workpiece W and directs the laser beam172 toward selected first molecules 392 a on a portion P₃ of theworkpiece W. The power, wavelength, and other laser beam parameters areselected based on the chemistry of the first molecules 392 so that theenergy from the laser beam 172 activates the selected first molecules392 a such that the molecules 392 a are inclined to react with asubsequent gas. More specifically, the energy from the laser beam 172breaks one or more of the bonds of the selected adsorbed molecules 392a, which destabilizes the molecules 392 a such that the molecules 392 aare inclined to react with the next molecule in the ALD sequence. As thelaser 170 moves across the workpiece W, the laser beam 172 activates theselected first molecules 392 a without exposing or activating aplurality of nonselected first molecules 392 b on the workpiece W.

FIG. 7B is a schematic side cross-sectional view of the workpiece Wafter dispensing a pulse of a second gas into the reaction chamber 120(FIG. 4) and depositing a layer of second molecules 394 (shown as 394 aand 394 b) from the second gas onto the workpiece W. The first andsecond gases can have the same or different compositions. The secondmolecules 394 a proximate to the activated first molecules 392 a reactwith the activated molecules 392 a to form a discrete film 395 on theworkpiece W. The second molecules 394 b proximate to the nonactivatedfirst molecules 392 b generally do not react with the nonactivatedmolecules 392 b.

FIG. 7C a schematic side cross-sectional view of the workpiece W afterremoving the nonreacted second molecules 394 b (FIG. 7B) from theworkpiece W. The nonreacted second molecules 394 b can be removed fromthe workpiece W and the reaction chamber 120 (FIG. 4) by dispensing apurge gas into the chamber 120 and/or drawing the molecules 294 b fromthe chamber 120 with the vacuum pump 140 (FIG. 4). In some embodiments,the nonactivated first molecules 392 b can also be removed from theworkpiece W; however, in other embodiments, the nonactivated firstmolecules 392 b may not be removed from the workpiece W. In either case,the process can be repeated to build additional layers (shown in hiddenlines as 395 b and 395 c) and form a feature 399 on the workpiece W.

In other embodiments, the laser 170 can irradiate the selected portionP₃ of the workpiece W after the second molecules 394 have been depositedonto the workpiece W. For example, in one method, a layer of firstmolecules 392 are deposited across the workpiece W, and then thereaction chamber 120 can be optionally purged. Next, a layer of secondmolecules 394 are deposited across the workpiece W, and then the laser170 irradiates the selected portion P₃ of the workpiece W to activatethe selected first and/or second molecules and catalyze the reactionbetween the selected molecules.

In additional embodiments, the methods described above with reference toFIGS. 7A-7C can also be used in a CVD process. For example, in one CVDprocess, a layer of first molecules can be deposited onto a workpiece,and the laser can activate a selected portion of the first molecules.Next, a plurality of second molecules can be deposited onto and reactwith the activated first molecules. Alternatively, as described above,the laser can irradiate the selected portion of the workpiece after alayer of second molecules have been deposited to catalyze the reactionbetween the selected first and second molecules.

D. Additional Embodiments of Deposition Systems

FIG. 8 is a schematic representation of a system 400 for depositingmaterials onto a microfeature workpiece W in accordance with anotherembodiment of the invention. The illustrated system 400 is generallysimilar to the system 100 described above with reference to FIG. 4. Forexample, the illustrated system 400 includes a reactor 410 having areaction chamber 420 coupled to the gas supply 130 and the vacuum pump140. The illustrated reaction chamber 420 includes a laser 470 (shownschematically) for producing a laser beam 472 along a path, a reflector478 positioned along the path of the laser beam 472, and a positioningdevice 480 (shown schematically) for moving the reflector 478 relativeto the workpiece W. The laser 470 can be fixed relative to the workpieceW and configured to pivot about the Z axis. The positioning device 480can move the reflector 478 side to side (e.g., X direction) and forwardand backward (e.g., Y direction) to reflect the laser beam 472 towardthe selected portion of the workpiece W.

FIG. 9 is a schematic representation of a system 500 for depositingmaterials onto a microfeature workpiece W in accordance with anotherembodiment of the invention. The illustrated system 500 is generallysimilar to the system 100 described above with reference to FIG. 4. Forexample, the illustrated system 500 includes a reactor 510 having areaction chamber 520 coupled to the gas supply 130 and the vacuum pump140. The illustrated reaction chamber 520 includes a laser 570 (shownschematically) for generating a laser beam 572 (shown in hidden lines),a workpiece support 150 for carrying the workpiece W, and a positioningdevice 580 (shown schematically) attached to the workpiece support 150for moving the workpiece W relative to the laser 570. For example, thepositioning device 580 can move the workpiece support 150 from a firstposition (shown in solid lines) in which the workpiece W is oriented fordeposition to a second position (shown in broken lines) in which theworkpiece W is oriented for irradiation.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from thespirit and scope of the invention. For example, any one of the systems100, 400 and 500 described above with reference to FIGS. 4, 8 and 9 canbe used to perform any one of the methods described above with referenceto FIGS. 5-7. Accordingly, the invention is not limited except as by theappended claims.

1. A system for depositing materials onto a surface of a microfeatureworkpiece, the system comprising: a gas supply assembly having a gassource; a gas phase reaction chamber for carrying the microfeatureworkpiece; a gas distributor carried by the reaction chamber and coupledto the gas supply assembly; an energy source positioned to selectivelyirradiate portions of the microfeature workpiece; and a controlleroperably coupled to the energy source and the gas supply assembly, thecontroller having a computer-readable medium containing instructions toperform a method comprising— depositing molecules of a gas onto themicrofeature workpiece in the reaction chamber; and selectivelyirradiating a first portion of the molecules on the microfeatureworkpiece in the reaction chamber without irradiating a second portionof the molecules on the workpiece.
 2. The system of claim 1 wherein theenergy source comprises a laser configured for producing a laser beam toselectively irradiate the first portion of the molecules on themicrofeature workpiece.
 3. The system of claim 1 wherein the energysource comprises a laser configured for producing a laser beam, andwherein the system further comprises a positioning device coupled to thelaser for moving the laser to selectively direct the laser beam towardthe first portion of the microfeature workpiece.
 4. The system of claim1 wherein the energy source comprises a laser configured for producing alaser beam along a path, and wherein the system further comprises areflector positioned in the path of the laser beam to reflect the laserbeam toward the microfeature workpiece.
 5. The system of claim 1 whereinthe energy source comprises a laser configured for producing a laserbeam along a path, and wherein the system further comprises: a reflectorpositioned in the path to reflect the laser beam toward the microfeatureworkpiece; and a positioning device coupled to the reflector for movingthe reflector so that the reflector directs the laser beam toward thefirst portion of the microfeature workpiece.
 6. The system of claim 1wherein the energy source comprises a laser configured for producing alaser beam, and wherein the system further comprises: a workpiecesupport for carrying the microfeature workpiece; and a positioningdevice coupled to the workpiece support for moving the support to alignthe microfeature workpiece with the laser beam.
 7. A system fordepositing materials onto a surface of a microfeature workpiece, thesystem comprising: a gas supply assembly having a first gas source and asecond gas source; a gas phase reaction chamber for carrying themicrofeature workpiece; a gas distributor carried by the reactionchamber and coupled to the gas supply assembly; an energy sourcepositioned to selectively irradiate portions of the microfeatureworkpiece; and a controller operably coupled to the energy source andthe gas supply assembly, the controller having a computer-readablemedium containing instructions to perform a method comprising—depositing first molecules of a first gas onto the microfeatureworkpiece; irradiating a first portion of the first molecules on themicrofeature workpiece without irradiating a second portion of the firstmolecules on the workpiece; and depositing second molecules of a secondgas onto at least one of the first and second portions of the firstmolecules on the microfeature workpiece.
 8. The system of claim 7wherein the energy source comprises a laser configured for producing alaser beam to selectively irradiate the first portion of the firstmolecules on the microfeature workpiece.
 9. The system of claim 7wherein the energy source comprises a laser configured for producing alaser beam along a path, and wherein the system further comprises areflector positioned in the path of the laser beam to reflect the laserbeam toward the microfeature workpiece.
 10. A system for depositingmaterials onto a surface of a microfeature workpiece, the systemcomprising: a gas supply assembly having a gas source; a gas phasereaction chamber for carrying the microfeature workpiece; a gasdistributor carried by the reaction chamber and coupled to the gassupply assembly; a laser positioned to produce a laser beam along a beampath for selectively impinging the surface of the microfeatureworkpiece; and a controller operably coupled to the laser and the gassupply assembly, the controller having a computer-readable mediumcontaining instructions to perform a method comprising— depositingmolecules of a gas onto the microfeature workpiece in the reactionchamber; and directing the laser beam toward a selected portion of themolecules on the microfeature workpiece in the reaction chamber todesorb the selected portion of the molecules.
 11. The system of claim10, further comprising a positioning device coupled to the laser formoving the laser to direct the laser beam toward the selected portion ofthe molecules on the microfeature workpiece.
 12. The system of claim 10,further comprising a reflector positioned in the beam path to reflectthe laser beam toward the microfeature workpiece.
 13. The system ofclaim 10, further comprising: a reflector positioned in the beam path toreflect the laser beam toward the microfeature workpiece; and apositioning device coupled to the reflector for moving the reflector sothat the reflector directs the laser beam toward the selected portion ofthe microfeature workpiece.
 14. A system for depositing materials onto asurface of a microfeature workpiece, the system comprising: a gas supplyassembly having a first gas source and a second gas source; a gas phasereaction chamber for carrying the microfeature workpiece; a gasdistributor carried by the reaction chamber and coupled to the gassupply assembly; a laser positioned to produce a laser beam along a beampath for selectively impinging the surface of the microfeatureworkpiece; and a controller operably coupled to the laser and the gassupply assembly, the controller having a computer-readable mediumcontaining instructions to perform a method comprising— depositingmolecules of a gas onto the microfeature workpiece in the reactionchamber; and irradiating a selected portion of the molecules on themicrofeature workpiece in the reaction chamber to activate the selectedportion of the molecules.
 15. The system of claim 14, further comprisinga positioning device coupled to the laser for moving the laser to directthe laser beam toward the selected portion of the molecules on themicrofeature workpiece.
 16. The system of claim 14, further comprising areflector positioned in the beam path to reflect the laser beam towardthe microfeature workpiece.
 17. The system of claim 14, furthercomprising: a reflector positioned in the beam path to reflect the laserbeam toward the microfeature workpiece; and a positioning device coupledto the reflector for moving the reflector so that the reflector directsthe laser beam toward the selected portion of the molecules on themicrofeature workpiece.